Magnetic suspension combined separation method for multi-metal associated ferromanganese ore based on hydrogen-based ore phase conversion

Abstract

A magnetic levitation combined separation method for multi-metal associated ferromanganese ore based on hydrogen-based ore phase conversion belongs to the technical field of beneficiation of ferromanganese ore, and comprises the following steps: grinding raw ferromanganese ore, and drying to obtain a roasted raw material; carrying out hydrogen-based mineral phase conversion suspension roasting on the roasting raw material, and carrying out a preheating oxidation process and a hydrogen reduction reaction process to obtain a conversion product; after roasting is completed, protective gas is introduced, a converted product is cooled, then low-intensity magnetic separation is conducted, and magnetic separation concentrate and magnetic separation tailings are obtained; and respectively carrying out reverse flotation to obtain iron ore concentrate and manganese ore concentrate. Compared with a traditional method, the method has the advantages that the agent dosage and energy consumption are remarkably reduced, the separation precision is improved, a brand new technical path is provided for economic and efficient development of the ferromanganese ore, the quality of the obtained finished product mineral is comprehensively guaranteed, and the technical requirements of high-purity iron ore concentrate and manganese ore concentrate are met.

Description

Technical Field

[0001] The invention belongs to the technical field of iron-manganese ore dressing, and in particular relates to a magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation. Background Art

[0002] The beneficiation technology of ferromanganese ore resources mainly includes gravity separation, magnetic separation, flotation and roasting combined process. However, the traditional process faces significant technical limitations when processing complex ferromanganese ores. Hydrogen-based ore phase transformation technology has become a research hotspot for solving the problem of complex ferromanganese ore resource utilization. This technology introduces hydrogen as a reducing agent to reduce weakly magnetic hematite to strongly magnetic magnetite, and at the same time reduce manganese minerals to weakly magnetic quartzite, thereby significantly amplifying the physical and chemical differences between ferromanganese minerals and gangue minerals, and improving the separation efficiency of magnetic separation and flotation. Compared with traditional reduction processes, hydrogen-based ore phase transformation technology has the following advantages: First, clean production can be achieved through hydrogen reduction, basically avoiding the emission of sulfur dioxide and nitrogen oxides; second, energy consumption is significantly reduced, which is in line with the development direction of green mining; third, the magnetism and stability of the reduction product are significantly improved, providing good conditions for subsequent sorting. However, hydrogen-based mineral phase transformation technology still faces many challenges in practical applications. For example, minerals of different particle sizes are prone to over-reduction or under-reduction during the roasting process, affecting the magnetic uniformity of the product. In addition, the silicon and aluminum impurities embedded in the minerals are difficult to completely remove during the subsequent flotation process, which restricts the grade improvement of iron concentrate and manganese concentrate.

[0003] Therefore, developing a complex iron-manganese ore dressing process based on hydrogen-based ore phase transformation technology, combined with the combined separation technology of magnetic separation and flotation, to achieve precise control and efficient separation of iron-manganese minerals and gangue minerals, can not only improve the grade and recovery rate of iron and manganese concentrates, but also provide technical support for the green and efficient utilization of complex iron-manganese ore resources. This is of great significance to ensuring the safety of the relevant industrial chain and achieving sustainable development of the mining industry. Summary of the invention

[0004] In view of the problems existing in the existing ferromanganese ore dressing technology, the present invention provides a magnetic levitation combined separation method for polymetallic associated ferromanganese ore based on hydrogen-based ore phase transformation, which mainly comprises six steps of grinding classification, hydrogen-based ore phase transformation, protective gas cooling, weak magnetic separation, reverse flotation separation of unqualified iron concentrate and reverse flotation separation of unqualified manganese concentrate, so as to achieve precise ore phase transformation of iron minerals and manganese minerals in ferromanganese ore and efficient and deep removal of useful minerals and gangue minerals therein.

[0005] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0006] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a ball mill and a classification device to obtain a ore material with a content of 18 μm to 74 μm and a proportion of 70% to 90%, and then dried to obtain a roasting raw material;

[0007] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is subjected to hydrogen-based mineral phase conversion suspension roasting, and a conversion product is obtained through a preheating oxidation process and a hydrogen reduction reaction process;

[0008] Step 3. Protective gas cooling: After the roasting is completed, the protective gas is introduced to cool the conversion product;

[0009] Step 4. Weak magnetic separation: weak magnetic separation is performed on the cooled product to obtain magnetic concentrate and magnetic tailings;

[0010] The magnetic separation concentrate is specifically unqualified iron concentrate, and the magnetic separation tailings are specifically unqualified manganese concentrate;

[0011] Step 5. Reverse flotation of unqualified iron ore concentrate: reverse flotation of unqualified iron ore concentrate by adopting the process of "one coarse, one fine and three sweeps" or "one coarse, one fine and four sweeps" to obtain iron ore concentrate;

[0012] In the reverse flotation process, the collector used is a combined collector A, specifically dodecylamine and sodium lauryl sulfonate; the inhibitor is carboxymethyl cellulose, and the pH adjuster is sodium hydroxide and hydrochloric acid;

[0013] Step 6. Reverse flotation of unqualified manganese concentrate: The reverse flotation process of the unqualified manganese concentrate is the same as that in step 5 to obtain manganese concentrate;

[0014] In the reverse flotation process, the collector used is a combined collector B, specifically sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride; the inhibitor is tannic acid, and the pH adjuster is sodium hydroxide and hydrochloric acid.

[0015] in:

[0016] In the step 1, the iron minerals in the ferromanganese ore include hematite, limonite, goethite and siderite, the manganese minerals include pyrolusite and rhodochrosite, and the gangue minerals include diaspore and quartz.

[0017] In the step 1, the ball milling slurry concentration is 35% to 65%.

[0018] In step 2, the preheating oxidation process is specifically as follows: preheating the calcined raw material in an air atmosphere at 100°C to 300°C to completely remove crystal water and adsorbed water, and then calcining in an oxygen atmosphere at 700°C to 900°C for 5min to 30min.

[0019] The reaction equation involved in the preheating process is as follows:

[0020] Fe2O3·nH2O→Fe2O3+nH2O

[0021] MnCO3→MnO2+CO2

[0022] The reaction equations involved in the oxidation process are as follows:

[0023] 4FeCO3+O2→2Fe2O3+4CO

[0024] 4Fe3O4+O2→6Fe2O3

[0025] 6MnO+O2→2Mn3O4

[0026] 3MnO2→Mn3O4+O2.

[0027] In step 2, the hydrogen reduction reaction process is specifically as follows: the roasted ore powder is reduced in a hydrogen atmosphere at 400°C to 700°C, the reducing gas concentration is 10% to 35%, and the roasting gas flow rate per ton of roasted raw material is 1000m 3 / h~1600m 3 / h, the reduction time is 10min~40min.

[0028] The reaction equation involved in the reduction process is as follows:

[0029] 3Fe2O3+H2→2Fe3O4+H2O

[0030] MnO2+H2→MnO+H2O

[0031] 2Mn3O4+H2→6MnO+H2O.

[0032] The reaction equations involved in the gangue minerals are as follows:

[0033] Al2O3·nH2O→Al2O3+nH2O

[0034] α·SiO2→β·SiO2.

[0035] In the step 2, the conversion products obtained are specifically magnetite and harzburgite.

[0036] In step 3, the protective gas is nitrogen or other inert gas, the cooling time is 10 min to 30 min, and the cooling product temperature is ≤60°C.

[0037] In the step 4, the strength of the weak magnetic separation magnetic field is 1500Oe to 3500Oe.

[0038] In step 5, the reverse flotation process of one roughing, one fine and three sweeping is specifically as follows: after adding a collector, an inhibitor and a pH adjuster to the reverse flotation pulp in sequence, the reverse flotation pulp enters the roughing operation, and after the roughing operation is completed, a roughing concentrate pulp and a roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and after the sweeping operation is completed, a flotation tailing is obtained, and after adding a collector and a pH adjuster to the roughing concentrate pulp, the reverse flotation pulp enters the sweeping operation to obtain an iron concentrate and a concentrated tailing;

[0039] After the selected tailings are combined with the concentrate obtained from the first scavenging operation, they are returned to the roughing operation for reselection; the concentrate obtained from the second scavenging operation is returned to the first scavenging operation process for reselection, and the concentrate obtained from the third scavenging operation is returned to the second scavenging operation process for reselection;

[0040] The reverse flotation process of one coarse, one fine and four scavenging is specifically as follows: after the reverse flotation process of one coarse, one fine and three scavenging is completed, the obtained concentrate is returned to the third scavenging operation process for re-selection.

[0041] In the step 5, the mass ratio of dodecylamine to sodium lauryl sulfate is (2-6):1, the reverse flotation pulp concentration is 35wt%-45wt%, the inhibitor dosage is 0.5kg / t-1kg / t, the combined collector dosage is 0.2kg / t-0.8kg / t, sodium hydroxide is 0.25kg / t-0.4kg / t, and hydrochloric acid is 0.05kg / t-0.1kg / t. After adding the reagent, the pulp pH is 8.5-9.5.

[0042] In the step 6, the mass ratio of sodium dodecylbenzene sulfonate to octadecyltrimethylammonium chloride is (5-8):1, the reverse flotation pulp concentration is 30wt%-55wt%, the inhibitor dosage is 0.5kg / t-1.0kg / t, the combined collector dosage is 0.3kg / t-1.5kg / t, sodium hydroxide is 0.30kg / t-0.35kg / t, and hydrochloric acid is 0.05kg / t-0.08kg / t. After adding the reagent, the pulp pH is 8.5-9.5.

[0043] The iron concentrate grade is ≥60%, the iron recovery rate is ≥90%, the manganese concentrate grade is ≥30%, and the manganese recovery rate is ≥85%.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention utilizes a gas-solid two-phase fluidized reactor and combines low-temperature hydrogen reduction technology to achieve efficient mineral phase transformation of iron and manganese minerals. By converting hematite into strongly magnetic magnetite and pyrolusite into weakly magnetic harzburgite, the process achieves significant enhancement of mineral magnetism and comprehensive and uniform transformation of mineral phases. In addition, the process can complete efficient reduction reactions under low temperature conditions, avoiding the phenomenon of excessive energy consumption in traditional high-temperature roasting processes, further reducing the impact on the environment, and has significant energy-saving and environmental protection advantages.

[0046] 2. After the mineral phase transformation is completed, the present invention uses a high-purity inert gas (such as nitrogen or argon) to quickly cool the roasted product. The inert atmosphere can effectively isolate oxygen and avoid reverse oxidation of magnetite and secondary transformation of harzburgite during the cooling process. This cooling method ensures the stability of the reduction product and the magnetic retention of the target mineral, while significantly improving the separation performance of subsequent weak magnetic separation and reverse flotation. Through this process, the quality of the finished mineral is fully guaranteed, meeting the technical requirements of high-purity iron ore and manganese concentrate.

[0047] 3. The present invention proposes a multi-stage separation process that combines hydrogen-based ore phase transformation-weak magnetic separation-reverse flotation. The ore phase transformation process first gives iron minerals and manganese minerals different magnetic properties to achieve efficient preliminary separation of the two minerals in the weak magnetic separation stage. Subsequently, through the optimized reverse flotation process, special collectors and inhibitors are accurately added to further remove impurities such as silicon and aluminum to obtain high-purity iron concentrate and high-activity manganese concentrate. Compared with traditional methods, the present invention not only significantly reduces the amount of reagents and energy consumption, but also improves the separation accuracy, providing a new technical path for the economical and efficient development of iron and manganese ores.

[0048] 4. The present invention significantly reduces the energy consumption and pollutant emissions in traditional processes by optimizing mineral processing and roasting technology. Hydrogen is used as a reducing agent to replace traditional carbon-based reducing agents, achieving pollution-free emissions of carbon dioxide, sulfur dioxide and nitrogen oxides throughout the entire process. The present invention constructs a green and low-carbon process system from mineral processing to finished mineral production, promotes the efficient and clean utilization of iron and manganese ore resources, and meets the development needs of modern green mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The present invention discloses a process flow chart of a magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation. DETAILED DESCRIPTION

[0050] The following is a clear and complete description of the technical solutions in the implementation of the present invention in conjunction with the embodiments and the accompanying drawings. It should be noted that the embodiments described in the present invention are only used to further explain and illustrate, rather than to limit the scope of application. Based on the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the protection scope of the present invention.

[0051] In the iron-manganese ore used in the embodiment of the present invention, the iron minerals include hematite, limonite, goethite and siderite, the manganese minerals include pyrolusite and rhodochrosite, and the gangue minerals include diaspore and quartz.

[0052] The reverse flotation process of one roughing, one fine and three sweeping adopted by the present invention is specifically as follows: after adding a collector, an inhibitor and a pH adjuster to the reverse flotation pulp in sequence, the reverse flotation pulp enters the roughing operation, and after the roughing operation is completed, a roughing concentrate pulp and a roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and after the sweeping operation is completed, a flotation tailing is obtained, and after adding a collector and a pH adjuster to the roughing concentrate pulp, the reverse flotation pulp enters the sweeping operation to obtain a concentrate and a concentrated tailing;

[0053] After the selected tailings are combined with the concentrate obtained from the first scavenging operation, they are returned to the roughing operation for reselection; the concentrate obtained from the second scavenging operation is returned to the first scavenging operation process for reselection, and the concentrate obtained from the third scavenging operation is returned to the second scavenging operation process for reselection;

[0054] The reverse flotation process of one coarse, one fine and four scavenging is specifically as follows: after the reverse flotation process of one coarse, one fine and three scavenging is completed, the obtained concentrate is returned to the third scavenging operation process for re-selection.

[0055] Example 1

[0056] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 21.35%, TMn 34.52%, SiO2 6.21%, and Al2O3 4.23%.

[0057] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation, the process flow chart of which is as follows Figure 1 As shown, the specific steps include:

[0058] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 72%, and a ball mill slurry concentration of 45%. After drying, the roasting raw material is obtained.

[0059] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 150°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 820°C for 25 minutes; the roasted ore powder is reduced in a hydrogen atmosphere at 580°C, the reducing gas concentration is 30%, and the corresponding roasting gas flow rate per ton of roasted raw material is 1500m 3 / h, the reduction time is 35min, and the conversion products magnetite and harzburgite are obtained.

[0060] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 25 minutes and the cooling product temperature is 40°C.

[0061] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 1500Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0062] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and three sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 40wt%, sodium hydroxide (dosage 0.35kg / t) and hydrochloric acid (dosage 0.08kg / t) are added to the pulp, the pulp pH is adjusted to 8.8, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 2:1, dodecylamine and sodium lauryl sulfonate, dosage 0.6kg / t) and inhibitor carboxymethyl cellulose (dosage 0.8kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0063] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 9.0, and then combined collector A (dosage 0.3kg / t) is added to finally obtain iron concentrate with a product grade of 62.25% and a recovery rate of 92.72%.

[0064] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and three sweeping". The specific reverse flotation process is: the pulp concentration is controlled at 40wt%, sodium hydroxide (dosage 0.32kg / t) and hydrochloric acid (dosage 0.06kg / t) are added to the pulp, the pulp pH is adjusted to 8.7, and the combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 8:1, dosage 0.8kg / t) and inhibitor tannic acid (dosage 0.7kg / t) are added at the same time, and the roughing operation is entered. After the roughing is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding collectors. After the sweeping is completed, the flotation tailings are obtained.

[0065] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 9.2, and then combined collector B (dosage 0.4kg / t) is added to finally obtain manganese concentrate with a product grade of 54.73% and a recovery rate of 85.86%.

[0066] Example 2

[0067] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 42.72%, TMn 16.81%, SiO2 12.15%, and Al2O3 5.84%.

[0068] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0069] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 76%, and the ball milling slurry concentration is 60%. After drying, the roasting raw material is obtained.

[0070] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 200°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 880°C for 15 minutes. The roasted ore powder is reduced in a hydrogen atmosphere at 630°C, the reducing gas concentration is 35%, and the roasting gas flow rate per ton of roasted raw material is 1300m 3 / h, the reduction time is 35min, and the conversion products magnetite and harzburgite are obtained.

[0071] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 25 minutes and the cooling product temperature is 30°C.

[0072] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2000Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0073] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 38wt%, sodium hydroxide (dosage 0.28kg / t) and hydrochloric acid (dosage 0.07kg / t) are added to the pulp, the pulp pH is adjusted to 8.7, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 3:1, dosage 0.5kg / t) and inhibitor carboxymethyl cellulose (dosage 0.7kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0074] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.9, and then combined collector A (dosage 0.25kg / t) is added to finally obtain iron concentrate with a product grade of 66.15% and a recovery rate of 93.92%.

[0075] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is: the pulp concentration is controlled at 35wt%, sodium hydroxide (dosage 0.30kg / t) and hydrochloric acid (dosage 0.05kg / t) are added to the pulp, the pulp pH is adjusted to 8.5, and the combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 5:1, dosage 1.2kg / t) and inhibitor tannic acid (dosage 0.8kg / t) are added at the same time, and the roughing operation is entered. After the roughing is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding collectors. After the sweeping is completed, the flotation tailings are obtained.

[0076] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.8, and then combined collector B (dosage 0.3kg / t) is added to finally obtain manganese concentrate with a product grade of 31.30% and a recovery rate of 87.82%.

[0077] Example 3

[0078] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 32.41%, TMn 17.12%, SiO2 13.93%, and Al2O3 8.95%.

[0079] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0080] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 74%, and a ball mill slurry concentration of 52%. After drying, the roasting raw material is obtained.

[0081] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 220°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 760°C for 18 minutes; the roasted ore powder is reduced in a hydrogen atmosphere at 650°C, the reducing gas concentration is 25%, and the roasting gas flow rate per ton of roasted raw material is 1200m 3 / h, the reduction time is 30min, and the conversion products magnetite and harzburgite are obtained.

[0082] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 24 minutes and the cooling product temperature is 40°C.

[0083] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 1800 Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0084] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and three sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 43wt%, sodium hydroxide (dosage 0.4kg / t) and hydrochloric acid (dosage 0.05kg / t) are added to the pulp, the pulp pH is adjusted to 8.9, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 4:1, dodecylamine and sodium lauryl sulfonate, dosage 0.3kg / t) and inhibitor carboxymethyl cellulose (dosage 0.5kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0085] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 9.3, and then combined collector A (dosage 0.6kg / t) is added to finally obtain iron concentrate with a product grade of 67.11% and a recovery rate of 90.18%.

[0086] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is: the pulp concentration is controlled at 45wt%, sodium hydroxide (dosage 0.35kg / t) and hydrochloric acid (dosage 0.08kg / t) are added to the pulp, the pulp pH is adjusted to 9.0, and the combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 5:1, dosage 0.5kg / t) and inhibitor tannic acid (dosage 1.0kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0087] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.9, and then combined collector B (dosage 0.6kg / t) is added to finally obtain manganese concentrate with a product grade of 52.50% and a recovery rate of 88.24%.

[0088] Example 4

[0089] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 30.91%, TMn 10.24%, SiO2 26.50%, and Al2O3 7.52%.

[0090] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0091] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 88%, and a ball mill slurry concentration of 46%. After drying, the roasting raw material is obtained.

[0092] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 150°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 900°C for 23 minutes. The roasted ore powder is reduced in a hydrogen atmosphere at 700°C, with a reducing gas concentration of 30%. The corresponding roasting gas flow rate per ton of roasted raw material is 1350m 3 / h, the reduction time is 28min, and the conversion products magnetite and harzburgite are obtained.

[0093] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 30 minutes and the cooling product temperature is 50°C.

[0094] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2500Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0095] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 37wt%, sodium hydroxide (dosage 0.32kg / t) and hydrochloric acid (dosage 0.1kg / t) are added to the pulp, the pulp pH is adjusted to 8.6, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 5:1, dosage 0.7kg / t) and inhibitor carboxymethyl cellulose (dosage 1.0kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0096] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.8, and then combined collector A (dosage 0.4kg / t) is added to finally obtain iron concentrate with a product grade of 61.85% and a recovery rate of 91.32%.

[0097] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is: the pulp concentration is controlled at 38wt%, sodium hydroxide (dosage 0.33kg / t) and hydrochloric acid (dosage 0.07kg / t) are added to the pulp, the pulp pH is adjusted to 9.1, and the combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 6:1, the dosage is 1.0kg / t), and the inhibitor tannic acid (dosage 0.6kg / t) are added at the same time, and the roughing operation is entered. After the roughing is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping is completed.

[0098] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.7, and then combined collector B (dosage 0.5kg / t) is added to finally obtain manganese concentrate with a product grade of 49.78% and a recovery rate of 89.85%.

[0099] Example 5

[0100] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 33.57%, TMn 22.85%, SiO2 12.14%, and Al2O3 5.96%.

[0101] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0102] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 75%, and a ball mill slurry concentration of 52%. After drying, the roasting raw material is obtained.

[0103] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 180°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 900°C for 20 minutes. The roasted ore powder is reduced in a hydrogen atmosphere at 600°C, the reducing gas concentration is 25%, and the corresponding roasting gas flow rate per ton of roasted raw material is 1200m 3 / h, the reduction time is 35min, and the conversion products magnetite and harzburgite are obtained.

[0104] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 25 minutes and the cooling product temperature is 50°C.

[0105] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2000Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0106] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and three sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 40wt%, sodium hydroxide (dosage 0.35kg / t) and hydrochloric acid (dosage 0.08kg / t) are added to the pulp, the pulp pH is adjusted to 8.9, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 4:1, dosage 0.6kg / t) and inhibitor carboxymethyl cellulose (dosage 0.8kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0107] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.9, and then combined collector A (dosage 0.6 kg / t) is added to finally obtain iron concentrate with a product grade of 63.10% and a recovery rate of 91.52%.

[0108] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 42wt%, sodium hydroxide (dosage 0.30kg / t) and hydrochloric acid (dosage 0.07kg / t) are added to the pulp, the pulp pH is adjusted to 8.8, and combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 6:1, dosage 1.2kg / t) and inhibitor tannic acid (dosage 0.7kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding collectors, and the flotation tailings are obtained after the sweeping operation.

[0109] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.9, and then combined collector B (dosage 0.4kg / t) is added to finally obtain manganese concentrate with a product grade of 48.21% and a recovery rate of 87.30%.

[0110] Example 6

[0111] This embodiment uses a certain iron manganese ore as a raw material, and the main chemical components are TFe 26.85%, TMn 31.12%, SiO2 8.95%, and Al2O3 5.32%.

[0112] A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation specifically comprises the following steps:

[0113] Step 1. Grinding and classification: The raw iron-manganese ore is fed into a conical ball mill and a classifying device to obtain a ore material with a content of 18 μm to 74 μm accounting for 80%, and the ball milling slurry concentration is 45%. After drying, the roasting raw material is obtained.

[0114] Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is sent to a suspension roasting furnace for hydrogen-based mineral phase conversion suspension roasting. First, the roasted raw material is preheated in an air atmosphere at 200°C to completely remove crystal water and adsorbed water, and then roasted in an oxygen atmosphere at 900°C for 18 minutes. The roasted ore powder is reduced in a hydrogen atmosphere at 650°C, the reducing gas concentration is 35%, and the corresponding roasting gas flow rate per ton of roasted raw material is 1400m 3 / h, the reduction time is 35min, and the conversion products magnetite and harzburgite are obtained.

[0115] Step 3. Cooling with protective gas: After roasting, nitrogen is introduced and the conversion product is cooled in a nitrogen atmosphere to prevent reverse oxidation of harzburgite to tetravalent manganese or trivalent manganese and reverse oxidation of magnetite to hematite. The cooling time is 20 minutes and the cooling product temperature is 60°C.

[0116] Step 4. Weak magnetic separation: The cooled product is subjected to weak magnetic separation with a magnetic field strength of 2400 Oe to obtain magnetic concentrate, i.e., unqualified iron concentrate, and magnetic tailings, i.e., unqualified manganese concentrate.

[0117] Step 5. Reverse flotation of unqualified iron concentrate: The unqualified iron concentrate is reversely flotated by the process of "one roughing, one fine and four sweeping". The specific reverse flotation process is as follows: the pulp concentration is controlled at 40wt%, sodium hydroxide (dosage 0.35kg / t) and hydrochloric acid (dosage 0.07kg / t) are added to the pulp, the pulp pH is adjusted to 8.9, and combined collector A (dodecylamine and sodium lauryl sulfonate mixed in a mass ratio of 3:1, dosage 0.5kg / t) and inhibitor carboxymethyl cellulose (dosage 0.8kg / t) are added at the same time, and the roughing operation is entered. After the roughing operation is completed, the roughing concentrate pulp and the roughing tailing pulp are obtained; the roughing tailing pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping operation.

[0118] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 9.1, and then combined collector A (dosage 0.6kg / t) is added to finally obtain iron concentrate with a product grade of 62.75% and a recovery rate of 90.33%.

[0119] Step 6. Reverse flotation of unqualified manganese concentrate: The unqualified manganese concentrate is reversely flotated by the process of "one roughing, one fine and three sweeping". The specific reverse flotation process is: the pulp concentration is controlled at 42wt%, sodium hydroxide (dosage 0.30kg / t) and hydrochloric acid (dosage 0.06kg / t) are added to the pulp, the pulp pH is adjusted to 9.0, and the combined collector B (sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride mixed in a mass ratio of 5:1, dosage 1.2kg / t) and inhibitor tannic acid (dosage 0.8kg / t) are added at the same time, and the roughing operation is entered. After the roughing is completed, the roughing concentrate pulp and the roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and is further floated without adding a collector, and the flotation tailings are obtained after the sweeping is completed.

[0120] The roughing concentrate pulp enters the concentrating operation. Sodium hydroxide is first added to adjust the pulp pH to pH 8.8, and then combined collector B (dosage 0.4kg / t) is added to finally obtain manganese concentrate with a product grade of 52.65% and a recovery rate of 88.05%.

[0121] Comparative Example 1

[0122] The method steps are the same as those in Example 1, except that step 3 is not cooled by protective gas, but is directly cooled in the air, and the remaining implementation steps are the same. The results show that the grade of the iron concentrate obtained in step 5 is 61.24%, and the recovery rate is 82.56%, and the grade of the manganese concentrate obtained in step 6 is 43.12%, and the recovery rate is 65.78%. The possible reason is that due to the lack of protective atmosphere during the cooling process, the magnetite is partially reverse-oxidized to hematite, resulting in the weakening of the magnetism of the iron mineral, which affects the efficiency of iron-manganese separation during magnetic separation; at the same time, divalent manganese is oxidized to high-valent manganese during air cooling, which changes the surface chemical properties of the manganese mineral and reduces the adsorption capacity of the flotation agent. In addition, the properties of the gangue minerals failed to remain stable during the cooling process, which further reduced the removal efficiency of the silicon-aluminum gangue during the flotation process, and ultimately affected the grade and recovery rate of the iron concentrate and manganese concentrate.

[0123] Comparative Example 2

[0124] Same as Example 2, except that step 2 does not use hydrogen-based ore phase conversion technology, but adopts conventional high-temperature air roasting process, and the remaining implementation steps are the same. The results show that the grade of iron concentrate in step 5 drops to 59.83%, and the recovery rate is 78.21%; the grade of manganese concentrate obtained in step 6 drops to 43.57%, and the recovery rate is only 66.42%. The possible reason is that conventional high-temperature air roasting cannot achieve accurate ore phase conversion, resulting in the iron minerals not being completely converted into strongly magnetic magnetite, and the manganese minerals are not fully reduced to weakly magnetic quartzite, thereby weakening the differences in physical and chemical properties between iron and manganese minerals, and significantly reducing the magnetic separation efficiency. In addition, the gangue minerals are not fully activated under high-temperature air roasting, and silicon-aluminum impurities are difficult to remove during flotation, which further affects the grade and recovery rate of iron concentrate and manganese concentrate, and increases the difficulty of separation.

Claims

1. A magnetic levitation combined separation method for polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation, characterized in that: The specific steps include: Step 1. Grinding and classification: The raw iron-manganese ore is fed into a ball mill and a classification device to obtain a ore material with a content of 18 μm to 74 μm and a proportion of 70% to 90%, and then dried to obtain a roasting raw material; Step 2. Hydrogen-based mineral phase conversion: The roasted raw material obtained in step 1 is subjected to hydrogen-based mineral phase conversion suspension roasting, and a conversion product is obtained through a preheating oxidation process and a hydrogen reduction reaction process; Step 3. Protective gas cooling: After the roasting is completed, the protective gas is introduced to cool the conversion product; Step 4. Weak magnetic separation: weak magnetic separation is performed on the cooled product to obtain magnetic concentrate and magnetic tailings; The magnetic separation concentrate is specifically unqualified iron concentrate, and the magnetic separation tailings are specifically unqualified manganese concentrate; Step 5. Reverse flotation of unqualified iron ore concentrate: reverse flotation of unqualified iron ore concentrate using the process of "one coarse, one fine and three sweeps" or "one coarse, one fine and four sweeps" to obtain iron ore concentrate; In the reverse flotation process, the collector used is a combined collector A, specifically dodecylamine and sodium lauryl sulfonate; the inhibitor is carboxymethyl cellulose, and the pH adjuster is sodium hydroxide and hydrochloric acid; Step 6. Reverse flotation of unqualified manganese concentrate: The reverse flotation process of the unqualified manganese concentrate is the same as that in step 5 to obtain manganese concentrate; In the reverse flotation process, the collector used is a combined collector B, specifically sodium dodecylbenzene sulfonate and octadecyltrimethylammonium chloride; the inhibitor is tannic acid, and the pH adjuster is sodium hydroxide and hydrochloric acid.

2. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In the step 1, the iron minerals in the ferromanganese ore include hematite, limonite, goethite and siderite, the manganese minerals include pyrolusite and rhodochrosite, and the gangue minerals include diaspore and quartz; and the ball mill slurry concentration is 35% to 65%.

3. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In step 2, the preheating oxidation process is specifically as follows: preheating the calcined raw material in an air atmosphere at 100°C to 300°C to completely remove crystal water and adsorbed water, and then calcining in an oxygen atmosphere at 700°C to 900°C for 5min to 30min.

4. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In step 2, the hydrogen reduction reaction process is specifically as follows: the roasted ore powder is reduced in a hydrogen atmosphere at 400°C to 700°C, the reducing gas concentration is 10% to 35%, and the roasting gas flow rate per ton of roasted raw material is 1000m 3 / h~1600m 3 / h, the reduction time is 10min~40min.

5. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In the step 2, the conversion products obtained are specifically magnetite and harzburgite.

6. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In step 3, the protective gas is nitrogen or other inert gas, the cooling time is 10 min to 30 min, and the cooling product temperature is ≤60°C.

7. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In the step 4, the strength of the weak magnetic separation magnetic field is 1500Oe to 3500Oe.

8. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In step 5, the reverse flotation process of one roughing, one fine and three sweeping is specifically as follows: after adding a collector, an inhibitor and a pH adjuster to the reverse flotation pulp in sequence, the reverse flotation pulp enters the roughing operation, and after the roughing operation is completed, a roughing concentrate pulp and a roughing tailings pulp are obtained; the roughing tailings pulp enters the sweeping operation, and after the sweeping operation is completed, a flotation tailing is obtained, and after adding a collector and a pH adjuster to the roughing concentrate pulp, the reverse flotation pulp enters the sweeping operation to obtain an iron concentrate and a concentrated tailing; After the selected tailings are combined with the concentrate obtained from the first scavenging operation, they are returned to the roughing operation for reselection; the concentrate obtained from the second scavenging operation is returned to the first scavenging operation process for reselection, and the concentrate obtained from the third scavenging operation is returned to the second scavenging operation process for reselection; The reverse flotation process of one coarse, one fine and four scavenging is specifically as follows: after the reverse flotation process of one coarse, one fine and three scavenging is completed, the obtained concentrate is returned to the third scavenging operation process for re-selection.

9. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1 is characterized in that: In the step 5, the mass ratio of dodecylamine to sodium lauryl sulfate is (2-6):1, the reverse flotation pulp concentration is 35wt%-45wt%, the inhibitor dosage is 0.5kg / t-1kg / t, the combined collector dosage is 0.2kg / t-0.8kg / t, sodium hydroxide is 0.25kg / t-0.4kg / t, and hydrochloric acid is 0.05kg / t-0.1kg / t. After adding the reagent, the pulp pH is 8.5-9.5; In the step 6, the mass ratio of sodium dodecylbenzene sulfonate to octadecyltrimethylammonium chloride is (5-8):1, the reverse flotation pulp concentration is 30wt%-55wt%, the inhibitor dosage is 0.5kg / t-1.0kg / t, the combined collector dosage is 0.3kg / t-1.5kg / t, sodium hydroxide is 0.30kg / t-0.35kg / t, and hydrochloric acid is 0.05kg / t-0.08kg / t. After adding the reagent, the pulp pH is 8.5-9.

5.

10. The magnetic levitation combined separation method of polymetallic associated iron-manganese ore based on hydrogen-based ore phase transformation according to claim 1, characterized in that: The iron concentrate grade is ≥60%, the iron recovery rate is ≥90%, the manganese concentrate grade is ≥30%, and the manganese recovery rate is ≥85%.

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